Tính nhẩm a) 8 . 24 . 6 + 12 . 4 . 52 + 2 . 22 . 24 b)18. 58 . 2 – 9 . 27 . 4 + 12 . 69 . 3 c)30 . 85 . 3 + 18 . 72 . 5 – 45 . 37 . 2 – 9 . 20 . 10

0 bình luận về “Tính nhẩm a) 8 . 24 . 6 + 12 . 4 . 52 + 2 . 22 . 24 b)18. 58 . 2 – 9 . 27 . 4 + 12 . 69 . 3 c)30 . 85 . 3 + 18 . 72 . 5 – 45 . 37 . 2 – 9 . 20 . 10”

1. `a) 8.24.6 + 12.4.52 + 2.22.24 `

   `= 48.24 + 48.52 + 48.22`

   `= 48. (24 + 52 + 22) `

   `= 48.98`

   `= 48.100 – 48.2`

   `= 4704`

   `b) 18.58.2 – 9.27.4 + 12.69.3 `

   `= 36.58 − 36.27 + 36.69`

   `= 36(58 – 27 + 69)`

   `= 36.100`

   `= 3600`

   `c) 30.85.3 + 18.72.5 – 45.37.2 – 9.20.10`

   `= 90.85 + 90.72 – 90.37 – 90.20`

   `= 90.(85 + 72 – 37 – 20)`

   `= 90.100`

   `= 9000`

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2. `a) 8 . 24 . 6 + 12 . 4 . 52 + 2 . 22 . 24`

   `=48.24+48.52+2.22.4.6`

   `=48.24+48.52+48.22`

   `=48.(24+52+22)`

   `=48.98`

   `=48.100-48.2`

   `=4800-96`

   `=4704.`

   `b)18. 58 . 2 – 9 . 27 . 4 + 12 . 69 . 3`

   `=36.58-36.27+36.69`

   `=36.(58-27+69)`

   `=36.100`

   `=3600.`

   `c)30 . 85 . 3 + 18 . 72 . 5 – 45 . 37 . 2 – 9 . 20 . 10`

   `=90.85+90.72-90.37-90.20`

   `=90.(85+72-37-20)`

   `=90.100`

   `=9000.`

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